Re: A simpl(e)ification
- To: mathgroup at smc.vnet.net
- Subject: [mg105794] Re: A simpl(e)ification
- From: Peter Breitfeld <phbrf at t-online.de>
- Date: Sat, 19 Dec 2009 06:26:21 -0500 (EST)
- References: <hgd7qr$bkk$1@smc.vnet.net>
Simplify doesn't like the b in the denominator (I don't know why), but Simplify[Im[Exp[-2 I a] 1/b], {a, b} \[Element] Reals && b != 0] will work. But usually it's easier to use ComplexExpand instead of Simplify, which treats all variables as Reals. Pianiel wrote: > Dear All, > > With Mathematica 7.0.1, the following expression; > > Simplify[ Im[E^(-2 I a) b], Assumptions -> Element[a, Reals] && > Element[b, Reals]] > > gives > > -b Sin[2 a] > > But: > > Simplify[ Im[E^(-2 I a) 1/b], Assumptions -> Element[a, Reals] && > Element[b, Reals]] > > gives > > Im[E^(-2 I a)/b] > > So we see that the Im[] is not simplified. Why? > > Any idea how to help mathematica to handle the simplification shown in > the second example. It seems to be so similar to the first kind... > > Thanks in advance > > Pianiel > -- _________________________________________________________________ Peter Breitfeld, Bad Saulgau, Germany -- http://www.pBreitfeld.de